Ordering Pierluisi to step aside, Judge Rafael Martínez Torres said a 2005 legislative amendment to the law of succession, called Law 7 violates the commonwealth's constitution. The measure said the secretary of state was allowed to succeed to the governor's office, even if he or she had been approved by only one chamber of Puerto Rico's congress.

As a result, the Supreme Court voided Pierluisi's swearing-in, because he was not properly confirmed as secretary of state by both Puerto Rico's Senate and House. Only the House of Representatives weighed in.

Pierluisi was nominated to be secretary of state by the former governor, Ricardo Rosselló, who resigned last Friday amid public protests and a scandal over a thread of homophobic and misogynistic texts.

Pierluisi said previously that he would respect whatever ruling the Supreme Court made.

The island's constitution called for the secretary of state to be first in the line of gubernatorial succession. The next person in line was Wanda Vázquez, who stated in late July that she had "no interest" in assuming the post.